In total, 21 COL4A1 and 3 COL4A2 mutations were identified, mostly in children with porencephaly or other patterns of parenchymal hemorrhage, with a high de novo mutation rate of 40% (10/24).
Our data showed that fetal intraventricular hemorrhage is not associated with COL4A1 and COL4A2 mutations in the absence of porencephaly, recurrent hemorrhage, and other organ bleeding.
Here, we report the identification of a novel dominant G702D mutation in the collagen domain of COL4A2 (collagen IV alpha chain 2) in a family displaying porencephaly with reduced penetrance.
We hypothesized that COL4A2 mutations confer genetic predisposition to porencephaly, therefore we sequenced COL4A2 in the family members and characterized clinical, neuroradiological and biochemical phenotypes.